February 12, 2018

expert reaction to impact of arthritis drug on dementia in rheumatoid arthritis patients

Researchers publishing a new study in Alzheimer’s and Dementia, report that users of classical disease modifying antirheumatic drugs were at reduced risk of dementia.

Dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said:

“There is increasing evidence of a key role for inflammation in diseases like Alzheimer’s and this has led researchers to investigate whether drugs used to treat inflammatory diseases, like rheumatoid arthritis, could also benefit people with dementia. Using good quality data from a large number of people, the experienced scientists conducting this research found that people who took certain types of arthritis drugs had a lower risk of dementia than people not taking this treatment.

“While these findings are interesting, it is not possible to rule out other factors that could have influenced dementia risk in this study, and the only way to tell if these drugs could help to tackle diseases like Alzheimer’s is through comprehensive clinical trials. In the past, a number of anti-inflammatory approaches have been explored as potential Alzheimer’s treatments, but with little evidence of benefits. People should only take these drugs if they have been prescribed to them by their doctor.”

Dr James Pickett, Head of Research, Alzheimer’s Society, said:

“This research suggests drugs used to control inflammation in rheumatoid arthritis may reduce the risk of dementia – but as it was an observational study, not a clinical trial, further research is needed before we can draw any firm conclusions about arthritis drugs as a treatment for dementia.

“It’s vital to explore whether drugs developed for other conditions also have benefits for dementia, as it could make it much quicker to get new drugs to the people who desperately need them. Alzheimer’s Society is prioritising this approach to research and currently funding a study to see whether arthritis drugs can boost memory and reduce dementia risk.”

“This study looked at people diagnosed with rheumatoid arthritis on GP databases. Rates of dementia were lower in people who had been treated with immune therapies for arthritis, compared to those who had not.

“While one might immediately think that this means immune drugs could treat dementia, there are several confounds. The patients selected for immune therapies might have differed from those selected not to have immune therapies. So, the two groups being compared may have been significantly different at the start in ways that cannot be measured using retrospective data. The total number of people with dementia in this study was low (~50 after 5 years in the treatment group) meaning effects can more easily be inflated (or lost) by chance. The effect of immune therapies might be different in people with rheumatoid compared to those without rheumatoid arthritis. Therefore, this result would not generalise to the whole population.

“This study is not designed in a way that allows us to change clinical practice to treat dementia with arthritis drugs. There are significant clinical risks with using arthritis drugs and we do not have convincing evidence that people with dementia would benefit. Nevertheless, this avenue is extremely interesting for future research and is the focus of upcoming trials.”

“This is an interesting finding. The study is an examination of the national CPRD database in those with rheumatoid disease comparing those who received these disease modifying medications compared to those who did not. The finding of a reduced incidence of dementia is interesting and should be hypothesis generating certainly.

“There has always been an interest in this area since early reports of a lower incidence of dementia in people with Rheumatoid arthritis and the possible role for example of nonsteroidal anti-inflammatory drugs. Studies that have investigated the nonsteroidal effects have been negative. The press release in this case is reflective of the study and very factual with no over-speculation. There are a number of studies both reported and ongoing that relate to a variety of aspects of the CPRD database so the quality seems good. The analysis is appropriate and the conclusions reflect the analysis.

“There has been an increasing interest in the area of inflammation related to dementia and there are a number of studies examining the basic science involved and also preliminary studies in patients. The literature has suggested that inflammatory mediators are important in dementia and there have been preliminary studies into “biologicals” such as etanercept as a result.

“The authors mention that the effects were stronger in those who used methotrexate in this study and also refer to the possibility that some people were also on biologicals but have not overstated this. The authors mention the potential limitations e.g. of validation of diagnosis of dementia and some other possible confounders but seem to have taken appropriate measures to allow for a large number of confounders.

“This study does provide some additional evidence related to the inflammatory basis of dementia and should be followed up as the authors suggest by appropriate clinical trials.”

* ‘Protective effect of antirheumatic drugs on dementia in rheumatoid arthritis patients’ by A. Judge et al. has been published in Alzheimer’s & Dementia.

Declared interests

Dr Elizabeth Coulthard: “I have no conflicts”

Prof. Peter Passmore: “I have collaborated with Professor Holmes in the past and work closely with Dr McGuinness but have no formal involvement in their Alzheimers Society funded research project””